My parents recently asked me to install an IP video surveillance camera at their house (for reasons). Since I already have a Linux server there running 24/7, it was only natural that I somehow set it up to record the camera’s video feed (mp4 over RTSP). After a bit of googling I found ZoneMinder, which looked like it did everything I needed. However, after wasting half a day fiddling with it, I realized that it is, although very complex and feature-rich, not up to my needs: no matter how you configure it, it will convert the video feed into thousands of JPEG files and store them randomly on the filesystem. It also uses a MySQL database to store its information (so extra dependencies), viewing the camera live is very slow (refreshes a static image every 4-5 seconds), replaying a recording needs the Java plug-in in your browser (which I don’t have on Ubuntu) and you have to “export” a movie clip (i.e. it has to convert all the images it saved back to a video). What a waste, but I can see how this solution could be the most compatible with all possible environments (camera types, OSes, etcetera). I was unable to set up authentication or a maximum total file size, either.

Being fed up with ZoneMinder, I ditched it and decided to try and hack together something of my own. After fiddling for the next half of the day with ffmpeg, I came up with a viable solution, in bash.

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#!/bin/bash

OUTPUT_DIR="/var/www/bashsurv"
FFMPEG_INPUT_FLAGS="-rtsp_transport tcp"
FFMPEG_SOURCE="rtsp://192.168.1.123/video.mp4"
FFMPEG_OUTPUT_FLAGS="-r 20 -acodec libspeex"
FFMPEG_OUTPUT_EXT="ogv"
CLIP_LENGTH=600 # seconds
TIMELIMIT=620 # seconds, allows for network timeout over CLIP_LENGTH
KEEP_FILES_FOR=10080 # minutes

while [ true ]; do
  avconv -timelimit $TIMELIMIT $FFMPEG_INPUT_FLAGS -i $FFMPEG_SOURCE -t $CLIP_LENGTH $FFMPEG_OUTPUT_FLAGS $OUTPUT_DIR/$(date +%F.%T).$FFMPEG_OUTPUT_EXT
  if [ $? -ne 0 ] ;
  then
    sleep 1m ;
  fi
  find $OUTPUT_DIR/ -type f -mmin +$KEEP_FILES_FOR -delete
done

Unfortunately, I was not able to just copy the codec, which would have been optimal in terms of resource (CPU/memory) usage on my server, but it doesn’t use up that much. Now I can set OUTPUT_DIR to somewhere in my /var/www, set up authentication on it via .htaccess and be done with it. Dad can now easily view the recordings using his browser, and if he really needs to view the live stream I can just bookmark the RTSP stream in VLC for him or something.

Bottom line: K.I.S.S.